The prevalence and diagnostic significance of Schneiderian first-rank symptoms in a random sample of acute psychiatric in-patients.

Ninety-nine acute in-patients were interviewed within four days of admission to hospital. The interview included items concerning all 11 first-rank symptoms. Two definitions (wide and narrow) of each first-rank symptom were employed. Three definitions of schizophrenia and a research diagnosis of major affective disorder were used to determine their relationship with first-rank symptoms. Of subjects with schizophrenia, 73% had first-rank symptoms, as had five (14%) of 34 subjects with affective disorder. The results do not support the hypothesis that first-rank symptoms are specific to schizophrenia, although the specificity of first-rank symptoms for schizophrenia increased if a narrow rather than a wide definition of symptoms was employed.